Design And Research Of High Speed Silicon Based Electro-optic Modulator For Modern Optical Communication

With the rapid development of optical communication technology,silicon-based optoelectronics has been more and more attention and development due to its excellent material properties of silicon and compatibility with the fabrication platform.Among them,high-speed optical transceivers based on silicon are the most important applications devices in the large data center and optical fiber communication processing networks at present because of its own device characteristics.The silicon-based high-speed modulators is the one of key components of optical transceivers,it closely affects the transceiver overall working state.In this paper,the design requirements of modern optical communication for silicon based optoelectronic integration is discussed.Starting from the characteristic of silicon,to introduce the silicon integration and electro-optical modulator.Then,The paper is carried out according to the sequence of the passive density waveguide array and the design of active electro-optical modulator.First of all,we put forward the method of configuration of density waveguide array.Then,the working principle and producing conditions of electro-optical modulators are studied and understood.Then,analyzing and determining the relevant modulation structure,especially the key structure—phase shifter and traveling wave electrode.After determining all the structural parameters of the electro-optical modulator,the high-speed electro-optical modulator is fabricated and tested.Finally,the test results show the finished of 25Gbps high-speed electro-optical modulator satisfy the design requirements.the thesis mainly contains the following parts:(1)A brief introduction of development of silicon photonics.then the paper discusses the research progress of integration of silicon-based photoelectric and electro-optic modulator,and to make clear the center and content of the paper.(2)The material properties of silicon are analyzed and understood.Then,making a brief summary and introduction for silicon device production process combined with today's microelectronics technology,to clearly defined our device's actual production process.(3)For the shortage of the existing analysis method of density waveguide array.Using the super lattice waveguide,to put forward our method of density waveguide array to solve the crosstalk of waveguide in design.(4)We analyze the structure of silicon-based electro-optical modulator according to the specific working principle.Firstly,the basic modulation structure is in turn selected:the optical MZI and the electrical PN junction.Then,the two most important structures-the phase shifter and the electrode are analyzed theoretically,in addition,combining with the design requirements and processing technology status of the device,structural parameters is simulated and analyzed,while the corresponding verification of the auxiliary test,through above study,the specific phase shifter structure and the type of electrode is selected.Finally,the selected resistance scheme to matched traveling wave electrode design,forming a complete design to meet the design requirements of high-speed electro-optical modulator.(5)we layout and draw the design of the previous part about the formation of high-speed silicon-based electro-optical modulator,and then sent the design to produce.At the same time in accordance with the design of the device to determine the corresponding test methods and start to build high-speed modulator test platform.After obtaining the finished chip,according to the design and test program,starting the test according to the design parameter sequence:passive waveguide,DC spectral characteristics,matched resistance reflectance,different signal rate modulation test,especially 25 Gbps or more high-speed signal modulation test.In the 20Gbps or more high speed test,due to the loss of high-frequency signal,using the pre-emphasis to enhance the high-frequency part of the signal to get effective high-speed modulation results.After the above tests,we comparative analysis and discussion the test results and design parameters or corresponding simulation data,accord with the design parameters of the device,then propose the corresponding improved optimization program.